| Brand Redux Ltd | Administrative & support | 2019 |
| Brandbay Ltd | Real estate | 2019 |
| Brands Enterprise Ltd | Wholesale & retail | 2025 |
| Brandwood Court Freehold Limited | Households | 2017 |
| Brandwork Digital Ltd | Professional & scientific | 2024 |
| Brangrey Developments Ltd | Construction | 2025 |
| Branix Consultancy Limited | Professional & scientific | 2019 |
| Branksea Catering Ltd | Administrative & support | 2001 |
| Branksea Oysters Limited | Agriculture & fishing | 2016 |
| Branksome Chase Residents Company Limited | Households | 2002 |
| Branksome Cleaning Services Limited | Administrative & support | 2016 |
| Branksome Estates Ltd. | Construction | 1953 |
| Branksome Hall Management Company Limited | Households | 1987 |
| Branksome Holdings Ltd | Financial services | 2024 |
| Branksome Masonic Hall,Limited | Other services | 1926 |
| Branksome Mews Management Company Limited | Real estate | 2002 |
| Branksome Park Lettings Ltd | Real estate | 2018 |
| Branksome Park Tennis Cafe Ltd | Arts & recreation | 2024 |
| Branksome Wood RTM Company Limited | Households | 2020 |
| Bransom Limited | Administrative & support | 2012 |
| Brantegra Ltd | Information & communication | 2026 |
| Brantwood Holdings Limited | Information & communication | 1997 |
| Bratherton Ward Ltd | Real estate | 2019 |
| Brattland Properties Ltd | Real estate | 2025 |
| Bravarie Ltd | Information & communication | 2025 |
| Brave Blue Limited | Arts & recreation | 2024 |
| Bravery Ltd | Wholesale & retail | 2014 |
| Bravo One by Whodaresgyms Ltd | Education | 2023 |
| Break Even Games Ltd | Information & communication | 2021 |
| Break Free Lifestyle Ltd | Administrative & support | 2017 |
| Breakaway Flat Management Company Limited | Households | 1991 |
| Breakin Hearts Limited | Arts & recreation | 2024 |
| Breakthrough Sports and Events Ltd | Wholesale & retail | 2019 |
| Breakwater Welding Ltd | Education | 2026 |
| Brearley-Smith Developments Limited | Construction | 1969 |
| Breathe Studios Limited | Health & social care | 2024 |
| Brecool Ltd | Wholesale & retail | 2025 |
| Breeze (Poole) Management Co Limited | Households | 2006 |
| Breeze (Southampton) Limited | Wholesale & retail | 1970 |
| Breeze Camper Hire Limited | Administrative & support | 2022 |
| Breeze Mobility Bournemouth Ltd | Wholesale & retail | 2017 |
| Breeze Motor Company Limited | Wholesale & retail | 2000 |
| Breeze Motorcycles Ltd | Wholesale & retail | 2022 |
| Breezebotanics Limited | Wholesale & retail | 2019 |
| Brenley Oak Ltd | Wholesale & retail | 2023 |
| Brentland Limited | Construction | 2015 |
| Breoco Ltd | Wholesale & retail | 2025 |
| Brett Pittwood Limited | Professional & scientific | 1997 |
| Brewers of Nuneham Limited | Financial services | 1961 |
| Brewers Quay (Weymouth) Ltd | Construction | 2022 |
| Brewery (Weymouth) Ltd | Construction | 2022 |
| Brewhouse Place Estate Management Ltd | Households | 2024 |
| Brewhouse Place Freehold Management Ltd | Households | 2024 |
| Brewsters (Poole) Ltd | Manufacturing | 2001 |
| Brian New Limited | Construction | 2019 |
| Brian Nicholls Architects Ltd | Professional & scientific | 2013 |
| Brick & Stone Supplies Limited | Wholesale & retail | 2008 |
| Bricklayers Limited | Construction | 1993 |
| Bride Place Limited | Real estate | 2023 |
| Bridge Dental Laboratory Limited | Manufacturing | 2002 |
| Bridge Environmental Services Ltd | Agriculture & fishing | 2021 |
| Bridge Initiative CIC | Administrative & support | 2025 |
| Bridge the GAP & Property Solutions Ltd | Financial services | 2024 |
| Bridgelink Recruitment Ltd | Administrative & support | 2026 |
| Bridgepoint Learning CIC | Education | 2026 |
| Bridges Financial Management Limited | Financial services | 2012 |
| Bridging & Development Finance Ltd. | Financial services | 2014 |
| Brie and ME Restaurant Limited | Hospitality | 2020 |
| Bright Beginnings Childcare Limited | Education | 2000 |
| Bright Construction Projects Limited | Construction | 2014 |
| Bright Financial Consulting Ltd | Extraterritorial | 2023 |
| Bright Futures Specialist Learning Limited | Education | 2025 |
| Bright Holdings (Hampshire) Limited | Professional & scientific | 2014 |
| Bright Light Citi Ltd | Information & communication | 2017 |
| Bright Sky Solar Limited | Energy | 2012 |
| Bright Systems Limited | Information & communication | 1993 |
| Bright Vans Limited | Manufacturing | 2024 |
| Brighter Outcomes Ltd | Information & communication | 2013 |
| Brighter PAY Limited | Administrative & support | 2023 |
| Brightline Commerce Ltd | Wholesale & retail | 2026 |
| Brightly Ltd | Real estate | 2024 |
| Brightmaths Ltd | Information & communication | 2022 |
| Brighton Transport Services Ltd | Transport & logistics | 2024 |
| Brighton Wonderland Ltd | Hospitality | 2015 |
| Brightor Ltd | Wholesale & retail | 2026 |
| Brightward Limited | Construction | 2025 |
| Brightwater Estates Limited | Real estate | 1997 |
| Brilliance Games Ltd | Information & communication | 2025 |
| Brilliant Luxury Co. Ltd | Manufacturing | 2025 |
| Brimble Gardens Ltd | Wholesale & retail | 2026 |
| Brindon Ltd | Wholesale & retail | 2026 |
| Bring to Bear Limited | Administrative & support | 2006 |
| Briqs AI Ltd | Information & communication | 2024 |
| Briqs Group Ltd | Professional & scientific | 2022 |
| Bristol Brazilian JIU Jitsu Limited | Education | 2020 |
| Brit Asia Global Limited | Wholesale & retail | 2025 |
| Brit-Chat Ltd | Education | 2022 |
| Britanix Ltd | Information & communication | 2025 |
| Britannia Gate Residents Association Limited | Households | 2001 |
| Britannia Worldwide Lettings Limited | Real estate | 2005 |